JPH05330231A - Recording method - Google Patents

Abstract

PURPOSE:To provide a recording method capable of certainly recording and erasing a visible image even under high temp. environment and capable of always obtaining a sharp recording image. CONSTITUTION:In a recording method for performing the recording and erasure of a visible image by a thermal head with respect to a recording medium capable of repeatedly performing the recording or erasure of the visible image by opacifying or transparentizing the medium under the control of heat energy, when the recording medium is repeatedly used, the visible image is recorded on the recording medium and, subsequently, the recording medium is cooled to predetermined temp. or lower.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention provides, for example, whitening or transparency by controlling heat energy,
The present invention relates to a recording method for recording or erasing a visible image on a recording medium capable of repeatedly recording or erasing a visible image using a thermal recording means such as a thermal head.

[0002]

2. Description of the Related Art A conventional hard copy forms an image on a recording medium such as paper from the outside with a visual material such as ink or toner, or, like a thermal recording paper,
A permanent image is recorded by providing a recording layer on a substrate such as paper and forming a visible image on the recording layer.

However, with the recent construction of various network networks and the widespread use of facsimiles and copiers, the rapid increase in the consumption of these recording media causes problems of natural destruction such as deforestation and social problems such as waste disposal. Is causing. In order to deal with these problems, it is strongly demanded to reduce the consumption amount of the recording medium such as reproduction of recording paper. In response to this problem, a recording medium that can be repeatedly recorded / erased has recently received attention.

Therefore, as a recording medium having such characteristics, there has been proposed a recording medium capable of reversibly changing both the transparent state and the cloudy state depending on the temperature applied to the recording material (for example, JP-A-55-154198). (See the official gazette).

In the transparent state, when the temperature is raised from T1 to T3, the recording medium changes from the transparent state to the cloudy state, and even when the temperature returns to T1, the cloudy state is maintained as it is. Then, when the temperature of the recording medium is raised from T1 to T2 and returned to T1 again, the cloudy state is changed to the transparent state, and the transparent state is maintained as it is. This change can be repeatedly reproduced.

[0006]

However, in a recording medium composed of a low molecular weight / polymer composite film recording material which repeatedly shows both cloudy and transparent states due to the temperature history as described above, cloudiness occurs in a high temperature environment, for example, 35 ° C. Even if an image is recorded, there is a problem that the image density is lowered and a semi-cloudy image is often obtained. Furthermore, even if this semi-white cloudy image is erased, there is a problem in that it cannot be completely erased and the white cloudy image disappears and remains. Therefore, an object of the present invention is to provide a recording method capable of surely recording or erasing a visible image even in a high temperature environment and always obtaining a clear recorded image.

[0007]

The recording method of the present invention uses a thermal recording medium capable of recording or erasing a visible image by making it cloudy or transparent by controlling thermal energy. A recording method for recording or erasing a visible image using a recording means, wherein during recording of a visible image, after making the recording medium cloudy by the thermal recording means,
It is characterized in that the recording medium is cooled.

In the recording method of the present invention, a thermal recording means is used for a recording medium capable of recording or erasing a visible image by making it cloudy or transparent by controlling thermal energy. A recording method for recording or erasing a visible image is characterized in that, when the visible image is erased, the recording medium is made cloudy by the thermal recording means and then the recording medium is cooled.

[0009]

Operation: For example, when the recording medium is repeatedly used,
After the visible image is recorded on the recording medium (after it becomes cloudy), the recording medium is cooled to a predetermined temperature or lower, so that the deterioration of the recording operation in the high temperature environment is resolved and the original environment is eliminated. It does not deteriorate even when returned to temperature. Therefore, it is possible to reliably record or erase a visible image even in a high temperature environment.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

First, the recording medium according to this embodiment will be described. The recording medium used in this example is a low-molecular / polymer composite film recording material that repeatedly shows both cloudy and transparent states depending on the temperature history, and is capable of repeatedly recording or erasing a visible image. For example, it has temperature-whitening / transparency characteristics as shown in FIG. That is,
In the transparent state, when the temperature is increased from T1 to T3, the transparent state becomes a cloudy state and the temperature is T1.
Even after returning to, the cloudiness is maintained. Then, when the temperature of the recording medium is raised from T1 to T2 and returned to T1 again, the cloudy state is changed to the transparent state, and the transparent state is maintained as it is. This change can be repeatedly reproduced.

Next, the operation of rewriting and recording a visible image by using a recording medium showing a state change as shown in FIG.
Will be explained. The example of FIG. 2 shows an example of rewriting and recording the character “L” on the character “I”. The feature of this recording operation is that the heating is performed not only for the heating element corresponding to the mark dot forming the image point but also for the heating element corresponding to the space dot not forming the image point.

First, as shown in FIG. 2A, the character "I" is recorded on the recording medium, and the character "I" is recorded on the recording medium.
As shown in (c), when the character "L" is rewritten and recorded, the process of FIG. 2 (b) is performed. That is, the heating resistor array 2 of a thermal head (not shown) as a thermal recording means is in contact with the recording medium 1, and the array of the heating resistors of the heating resistor array 2 is perpendicular to the recording direction. It is arranged so that. The heating resistors of the heating resistor array 2 are provided in a sufficient number to record the width of the recording medium 1.

In FIG. 2, 3 is a part of the already recorded image "I", 4 is a part of the currently recorded image "L", 5 is a part of the erased image "I", and 6 is a reproduced image. This is the recorded image portion. When recording on the recording medium 1, it suffices to raise the heating resistor corresponding to the pixel of interest (mark dot) to a temperature at which the recording medium 1 rises to the cloudy temperature range, regardless of the existing image. In this case, the heating resistor corresponding to the pixel of interest (space dot) may be raised to a temperature at which the recording medium 1 rises to the transparent temperature range regardless of the existing image.

As described above, by selectively heating the heating resistors of the heating resistor array 2 while conveying the recording medium 1 under the fixed heating element array 2 of the thermal head in the arrow direction, Rewriting recording is realized in which the new image 4 is recorded and the old image 3 is erased at the same time.

Now, when the present recording operation is performed in a high temperature environment, for example, 35 ° C., the present inventors obtain a semi-cloudy image because the density of the recorded image is lower than that in the normal temperature environment. I found that I couldn't. Further, it was found that even in image erasing, sufficient image erasing was not performed and an image residue was generated. Such a phenomenon did not disappear even if the recording energy and the erasing temperature were changed.

Therefore, when recording and erasing were carried out in an environmental test room with different ambient temperatures, the results shown in FIG. 3 were obtained. FIG. 3 schematically shows the relationship between the ambient environment temperature and the recording (whitening) density (O symbol) and the erasing (clearing) density (Δ symbol). The recording energy of the thermal head and the erasing temperature of the heat roller were set to optimum conditions at each environmental temperature.

The recording experiment was conducted as follows. An image was recorded on a recording medium in a transparent state which was left to stand at each environmental temperature, and the image density at that time was measured.
The erasure density was measured after leaving the recording medium on which a short pattern was recorded with a thermal head in a room temperature environment at each environment temperature.
The image density was measured by erasing by heating with a heat roller.

As is clear from FIG. 3, both the image density and the clearing density were significantly deteriorated from around 35 ° C., and both temperatures tended to approach each other. Such a tendency was the same not only in a specific recording medium but also in a plurality of recording media showing the state change shown in FIG.

As a result of various studies on such a phenomenon, after the recording is heated, if the recording medium is cooled to a temperature below the change point shown in FIG. It was found that the erase density did not deteriorate. Figure 1
The changes in the image density when the image is recorded and cooled (O symbol, solid line) and when not cooled (□ symbol, alternate long and short dash line) are schematically shown in FIG. In the figure, tH is the ambient temperature and tC is the cooling temperature.

FIG. 4 shows the structure of the experimental apparatus. In the figure, 1 is a recording medium showing the state change shown in FIG.
Reference numeral 11 is a thermal head for recording and erasing an image on the recording medium 1, 12 is a platen roller, 13 is a cooling water tank, and 14 is a cooling water circulating device with a temperature control function. The temperature-controlled water was circulated and supplied to the water tank 13 from a cooling water circulation device 14 connected to the water tank 13. Experiments were carried out using these devices while changing the environmental temperature in an environmental test room.

That is, after recording or erasing a visible image on the recording medium 1 with the thermal head 11, the recording medium 1 was immediately put into the water tank 13, immediately taken out from the water tank 13, and left at ambient temperature. And environmental temperature 35
℃ and 38 ℃, cooling water temperature 30 ℃, 2 respectively
Image densities and clearing densities were measured while changing to 5 ° C and 20 ° C. As a result, it was found that if the temperature after the image recording is cooled to a temperature below the threshold value indicating the recording operation failure, the image density and the clearing density are not deteriorated even when the temperature is returned to the environmental temperature where the operation failure occurs.

Further, there was no remarkable difference between the image density and the clearing density at each cooling water temperature, and the change represented by the change shown in FIG. 1 was shown. The setting of the cooling temperature can be experimentally obtained for the recording medium to be used as described above.

As described above, the recording method of the present embodiment is based on the above findings. After recording a visible image on a recording medium, the recording material is cooled to bring the recording medium to a predetermined temperature. It is characterized by cooling below.

As a result, the conventional deterioration of the recording operation under the high temperature environment is eliminated, and the deterioration of the recording operation does not occur again even if the original environment temperature is restored. Therefore, good repetitive recording can be performed in a wider environmental temperature range than the conventional recording method, and a visible image can be surely recorded or erased even in a high temperature environment, and a clear recorded image can always be obtained.

[0026]

As described in detail above, according to the present invention, it is possible to provide a recording method capable of surely recording or erasing a visible image even in a high temperature environment and always obtaining a clear recorded image.

[Brief description of drawings]

FIG. 1 is a diagram for explaining features of a recording operation of a recording apparatus according to an embodiment of the invention.

FIG. 2 is a diagram for explaining a recording operation of rewriting recording.

FIG. 3 is a diagram for explaining a recording operation failure in a high temperature environment.

FIG. 4 is a diagram showing a schematic configuration of a recording experiment device.

FIG. 5 is a diagram for explaining a state of a recording medium that can be changed to both a cloudy state and a transparent state depending on a history temperature.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Recording medium, 2 ... Heat-generating resistor array of thermal head, 11 ... Thermal head, 12 ... Platen roller, 13 ... Cooling water tank, 14 ... Cooling water circulation device.

Claims (2)

[Claims] 1. A recording medium capable of recording or erasing a visible image by making it cloudy or transparent by controlling thermal energy, and recording or erasing the visible image using a thermal recording means. A recording method for erasing, characterized in that at the time of recording a visible image, the recording medium is made cloudy by a thermal recording means, and then the recording medium is cooled. 2. A recording medium capable of recording or erasing a visible image by making it cloudy or transparent by controlling thermal energy, and recording or erasing the visible image using a thermal recording means. A recording method for erasing, characterized in that at the time of erasing a visible image, the recording medium is made cloudy by a thermal recording means, and then the recording medium is cooled.